The HashSpace class. More...

#include <C:/Users/Andres/source/repos/casm_viewer/external/tinc/external/allolib/include/al/spatial/al_HashSpace.hpp>

Classes
struct	Object
	container for registered spatial elements More...

struct	Query

struct	Voxel
	each Voxel contains a linked list of Objects More...

Public Member Functions
	HashSpace (uint32_t resolution=5, uint32_t numObjects=0)

uint32_t	dim () const
	the dimension of the space per axis:

uint32_t	maxRadius () const
	the maximum valid radius to query (half the dimension):

void	numObjects (int numObjects)
	get/set the number of objects:

uint32_t	numObjects () const

Object &	object (uint32_t i)
	get the object at a given index:

HashSpace &	move (uint32_t objectId, double x, double y, double z)
	set the position of an object:

template<typename T >
HashSpace &	move (uint32_t objectId, Vec< 3, T > pos)

HashSpace &	remove (uint32_t objectId)

double	wrap (double x) const
	wrap an absolute position within the space:

template<typename T >
Vec< 3, T >	wrap (Vec< 3, T > v) const

double	wrapRelative (double x) const

template<typename T >
Vec< 3, T >	wrapRelative (Vec< 3, T > v) const

Static Public Member Functions
static uint32_t	invalidHash ()
	an invalid voxel index used to indicate non-membership

Protected Member Functions
uint32_t	distanceSquared (double a1, double a2, double a3) const

uint32_t	hash (unsigned x, unsigned y, unsigned z) const

template<typename T >
uint32_t	hash (Vec< 3, T > v) const

uint32_t	hash (uint32_t x, uint32_t y, uint32_t z, uint32_t offset) const

template<typename T >
uint32_t	hash (Vec< 3, T > v, uint32_t offset) const

uint32_t	hashx (uint32_t v) const

uint32_t	hashy (uint32_t v) const

uint32_t	hashz (uint32_t v) const

Vec3i	unhash (uint32_t h) const

uint32_t	unhashx (uint32_t h) const

uint32_t	unhashy (uint32_t h) const

uint32_t	unhashz (uint32_t h) const

Static Protected Member Functions
static double	wrap (double x, double mod)

static double	wrap (double x, double lo, double hi)

Protected Attributes
uint32_t	mShift

uint32_t	mShift2

uint32_t	mDim

uint32_t	mDim2

uint32_t	mDim3

uint32_t	mWrap

uint32_t	mWrap3

int	mDimHalf

uint32_t	mMaxD2

uint32_t	mMaxHalfD2

std::vector< Object >	mObjects
	the array of objects

std::vector< Voxel >	mVoxels
	the array of voxels (indexed by hashed location)

std::vector< uint32_t >	mVoxelIndices
	a baked array of voxel indices sorted by distance

std::vector< uint32_t >	mDistanceToVoxelIndices
	a baked array mapping distance to mVoxelIndices offsets

std::vector< uint32_t >	mVoxelIndicesToDistance

Detailed Description

The HashSpace class.

HashSpace is a way to detect object collisions using a voxel grid The grid has a given resolution (no. voxel cells per side)

It is optimized for densely packed points and querying for nearest neighbors within given radii (results will be roughly sorted by distance).

Definition at line 76 of file al_HashSpace.hpp.

Constructor & Destructor Documentation

◆ HashSpace()

al::HashSpace::HashSpace	(	uint32_t	resolution = `5`,
		uint32_t	numObjects = `0`
	)

Construct a HashSpace locations will range from [0..2^resolution)

resolution can be 1 to 10; the dim is 2^resolution i.e. 2..1024 (the limit is 10 so that the hash can fit inside a uint32_t integer) default 5 implies 32 units per side

Parameters

resolution	determines the number of voxels as 2^resolution per axis
numObjects	set how many Object slots to initally allocate

Member Function Documentation

◆ remove()

HashSpace & al::HashSpace::remove ( uint32_t objectId )

inline

this removes the object from voxels/queries, but does not destroy it the objectId can be reused later via move()

Definition at line 507 of file al_HashSpace.hpp.

◆ wrapRelative()

double al::HashSpace::wrapRelative ( double x ) const

inline

wrap a relative vector within the space: use this when computing the vector between objects to properly take into account toroidal wrapping

Definition at line 264 of file al_HashSpace.hpp.

The documentation for this class was generated from the following file:

al_HashSpace.hpp

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions